| 摘要 |
1,223,950. Air conditioning units. MINE SAFETY APPLIANCES CO. 6 Nov., 1969 [28 Feb., 1969], No. 54497/69. Heading F4V. [Also in Division G3] Apparatus for supporting life in a sealed chamber comprises one or, as shown, two canisters 7, 12 containing a carbon dioxide absorbing and oxygen producing chemical, a canister 29 containing a carbon dioxide absorbing chemical only, air in the sealed chamber being passed by a blower 24 through the canisters 7, 12 until the oxygen concentration in the air reaches a predetermined maximum when the blower 24 is stopped and a blower 33 started to force the air through canister 29 until the oxygen concentration reaches a predetermined minimum, whereupon the cycle is repeated. The oxygen concentration is sensed by a polarographic cell 43 which controls a switch 41 in an electric circuit including the blowers 24, 33 through an amplifier and relay. The canisters 7, 12 contain potassium superoxide and the canister 29 lithium hydroxide, or soda lime. A top frame 13, 30 of each of the two units shown contains an air filter, and the canisters are held in position in the units by frames 9 and gaskets and by releasable straps 19, 31. |
